Mineral, petrography and petro-geochemical characteristics of diabasic dykes at the Trai Mat quarry, Da Lat City

Abstract

The diabasic dykes exposed at the Trai Mat quarry, Da Lat city intrude the granitoids of Ankroet complex (such as middle – coarse grained biotite granite and leucogranites. As can be seen in the field the thickess of these dykes vary from 0.5m to nearly 1.5 m extended north-south-east slope angles ranging from ~50 ⁰ to being upright (Orientation of lying 310Ð 50 ÷ 90 ^o). Petographical components consist of diabaz porphyrite. The main mineral components are plagioclase, pyroxene?, quartz, carbonate, chloride. Chemical components of rocks are: SiO₂: 54.34 %, K₂O: 2.43 %,Na₂O: 2,50 %. The content of W, Pb, U, Th, Hf, Rb, Au is higher.